diff --git a/CHANGES.rst b/CHANGES.rst
index ecaaa189d0ad7c279f9146945d5a871c975759d0..e1d5e876dc16299839003e1c1adf11043ff98bfa 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,3 +1,11 @@
+Changes in synapse v0.16.1-r1 (2016-07-08)
+==========================================
+
+THIS IS A CRITICAL SECURITY UPDATE.
+
+This fixes a bug which allowed users' accounts to be accessed by unauthorised
+users.
+
 Changes in synapse v0.16.1 (2016-06-20)
 =======================================
 
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 3cd79b1247436033e157ce41a5d083e19d73ff87..2750ad3f7a8c14e03dd88c9bba5e3da95bafc1b4 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -16,4 +16,4 @@
 """ This is a reference implementation of a Matrix home server.
 """
 
-__version__ = "0.16.1"
+__version__ = "0.16.1-r1"